PrOtein and WEight Loss in teenageRs (POWER)

The aim of the proposed study is to provide important data on weight loss efficacy in overweight and obese adolescents on an isocaloric higher protein diet vs a lower protein diet utilizing the U.S. Department of Agriculture (USDA) MyPlate nutrition guide. The investigators hypothesize that the higher protein diet will result in greater weight loss due to increased satiety and better dietary adherence.

Aim 1 is to test the efficacy of a personalized higher protein weight loss intervention compared to a lower protein intervention which use the USDA MyPlate nutrition guide. It is hypothesized that participants randomly assigned to the higher protein dietary treatment will lose more weight based on BMI-Z score over 12 weeks compared to participants in the lower dietary protein treatment. Aim 2 is to test if changes in subjective ratings of appetite differ by dietary treatment (i.e. protein intake). It is hypothesized that participants in the higher protein intervention will report a decrease in hunger and an increase in fullness compared to participants in the lower protein intervention. Aim 3 is to test if change in the hexosamine biosynthetic pathway (HBP) measured at the rate limiting step of glutamine fructose-6-phosphate amidotransferase (GFAT) and glycosylation measured as O-linked N-acetylglucosamine (GlcNAc) transferase (OGT) differ by dietary treatment. It is hypothesized that participants randomly assigned to the higher protein dietary treatment will have decreased change from baseline levels of GFAT and glycosylation (OGT) due to decreased carbohydrate intake compared to the lower protein treatment. Exploratory Aims: As exploratory aims, the investigators will test if the higher protein or lower protein dietary treatments differentially alter glucose, insulin, cholesterol, and triglycerides (markers of the metabolic syndrome).

Participants will receive an intervention specifically designed for adolescents and their group assignment that relies on nutrition education, nutritional counseling, social cognitive therapy, behavioral strategies, self-monitoring, portion size reduction, and increased physical activity. Participants will get an individualized dietary meal plan. Dietary counseling will be based on the MyPlate guidelines with extra attention and focus on appropriate protein food choice. Also in accordance to the MyPlate guidelines, all participants will be instructed to increase physical activity to 60 minutes a day as aerobic physical activity.

The higher protein group will be instructed to consume 30% of energy as protein, with 25% and 45% of energy from fat and carbohydrate, respectively.

The lower protein group will be instructed to consume 15% of energy as protein, with 25% and 60% of energy from fat and carbohydrate, respectively.

glutamine fructose-6-phosphate amidotransferase (GFAT) and glycosylation measured as O-linked N-acetylglucosamine (GlcNAc) transferase (OGT) measurement

Inclusion Criteria: Be male or female Be between the ages of 12 and 17, inclusive Be at or above the 85th BMI percentile (a number calculated from the participants height, weight, sex, and date of birth) Be willing to fast for 12 hours prior to clinic study visits 2 and 4 Be willing to participate in the research study Exclusion Criteria: Health Conditions: Has HIV or AIDS Has uncontrolled CVD or arrhythmia Has Type I or Type II diabetes. Is unable or unwilling to complete the study procedures Participant may not qualify for this study based on other exclusion criteria not listed. The study coordinator will go over this information in detail. Medications: Diuretics Beta-blocker Weight loss medications, diet pills Anti-inflammatory drugs (corticosteroid/anabolic steroid/NSAID) Antipsychotic medications Other medications that may affect fluid balance or weight Lifestyle: • Plans to move out of the study area within the next 4 months, or plan to be out of the study area for more than 3 weeks during the course of the study.